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Cougar
2004-Mar-06, 12:29 AM
What the heck is this?

http://www.xmission.com/~dcc/starswirl.jpg

JohnOwens
2004-Mar-06, 12:33 AM
Why, V838 Monocerotis, of course.

I happen to be downloading one of the bigger images right this moment. :wink:

Could also be confused for van Gogh's "Starry Night", according to some.

Andromeda321
2004-Mar-06, 12:41 AM
It is also my new wallpaper on my computer. Until the new Deep Field comes out, of course! :)

Taibak
2004-Mar-06, 12:51 AM
Taken a step further, V838 Monocerotis went off like a flashbulb a few years ago. Ever since, the light has been working its way through the cloud of dust surrounding the star, which made it look really cool. :-)

Incidentally, I presume V838 Monocerotis is the red star towards the middle of the cloud there. Is that a safe assumption?

Taibak

Cougar
2004-Mar-06, 01:10 AM
Incidentally, I presume V838 Monocerotis is the red star towards the middle of the cloud there. Is that a safe assumption?
I guess! Boy, you guys don't miss a thing. So the star sent out the big nonuniform blob of gas and dust quite some time ago, and then more recently sent out the "flashbulb" of photons to light it up?

George
2004-Mar-06, 02:15 AM
What the heck is this?

Wow. At first it reminded me of a blonde I once knew but then I noticed the lights inside. :) [sorry, just kiddin]

Truly a stunning image. Thanks Cougar!

The Bad Astronomer
2004-Mar-06, 02:21 AM
It either emitted that dust, or, more likely, formed from the same cloud. I don't think the star has been around very long, but I don't know what type it is and I am too lazy right now to look it up.

Maksutov
2004-Mar-06, 02:36 AM
Incidentally, I presume V838 Monocerotis is the red star towards the middle of the cloud there. Is that a safe assumption?
I guess! Boy, you guys don't miss a thing. So the star sent out the big nonuniform blob of gas and dust quite some time ago, and then more recently sent out the "flashbulb" of photons to light it up?

Here's (http://www.aavso.org/vstar/vsots/1202.shtml) a detailed article on Mono V838 as published by AAVSO. Lots of good info.

JohnOwens
2004-Mar-06, 02:37 AM
It either emitted that dust, or, more likely, formed from the same cloud. I don't think the star has been around very long, but I don't know what type it is and I am too lazy right now to look it up.

I had the same thought, that the star might have formed from the cloud rather than emitted it, but the brief description on the hubblesite.org page (http://www.hubblesite.org/newscenter/newsdesk/archive/releases/2004/10/) described it as "an expanding halo of light around a distant star", which to me sounds like it's being blown off of the star after all. On the other hand, that limited description isn't much to go on. :-?

Ut
2004-Mar-06, 03:31 AM
I had the same thought, that the star might have formed from the cloud rather than emitted it, but the brief description on the hubblesite.org page (http://www.hubblesite.org/newscenter/newsdesk/archive/releases/2004/10/) described it as "an expanding halo of light around a distant star", which to me sounds like it's being blown off of the star after all. On the other hand, that limited description isn't much to go on. :-?

That's halo of light. Doesn't say anything about the origin of the dust.

What is a light echo, anyway? Is it caused by only a little bit of the light being scattered? Assuming the dust to be surrounding the star, we can see through it. But in order to see what we do, there must be enough light reflecting off the dust and toward us. These to ideas are sort of conflicting for me.

Superluminal
2004-Mar-06, 03:43 AM
Post that over at GLP, and tell them it's the planet killer from Star Trek coming to get them, and that the little stars a all that's left of planet X. :P

gethen
2004-Mar-06, 04:32 AM
What the heck is this?


An object of incredible beauty, that's what. I saw this pic this a.m. on APOD and thought it one of the most beautiful astrophotos ever taken. VanGogh should be so lucky as to have painted something so spectacular.

dgruss23
2004-Mar-06, 01:01 PM
Tim Thompson (http://www.badastronomy.com/phpBB/viewtopic.php?t=4770&highlight=v838) has an outstanding web page on it.

newt
2004-Mar-07, 03:20 PM
This Spaceflightnow article has pics showing the expanding cloud over the past two years:

http://spaceflightnow.com/news/n0403/04spaceart/

Cheers. Newt.

ToSeek
2005-Feb-03, 05:53 PM
http://imgsrc.hubblesite.org/hu/db/2005/02/images/a/formats/web.jpg

Light Continues to Echo Three Years After Stellar Outburst (http://www.spaceref.com/news/viewpr.html?pid=16052)


The Hubble Space Telescope's latest image of the star V838 Monocerotis (V838 Mon) reveals dramatic changes in the illumination of surrounding dusty cloud structures. The effect, called a light echo, has been unveiling never-before-seen dust patterns ever since the star suddenly brightened for several weeks in early 2002.

Argos
2005-Feb-03, 06:29 PM
Beautiful. The problem with extreme image enhancement is that the public is led to believe that those things are solid. Try to explain the average joe that there´s very little matter there... :roll:

Kristophe
2005-Feb-03, 06:32 PM
Yeah, but if they were solid, we wouldn't be able to see them like this. The light is coming from inside the shell. A solid shell would block all of the light.

Argos
2005-Feb-03, 06:35 PM
Yes, but one could say that the stars on the foreground and around the shell illuminate the scene. :)

Kullat Nunu
2005-Feb-03, 06:39 PM
Quick brain teaser:

How it is possible that the V838 Monocerotis light echo has already an apparent radius of well over 6 light years even if the outburst happened only three years ago?

http://imgsrc.hubblesite.org/hu/db/2005/02/images/b/formats/compass_web.jpg

:)

Grey
2005-Feb-03, 07:17 PM
Quick brain teaser:

How it is possible that the V838 Monocerotis light echo has already an apparent radius of well over 6 light years even if the outburst happened only three years ago?

:)
I know! In fact, working out the numbers, that actually sounds just about right. Think for example about the light that was emitted in a cone at an angle of 45 degrees around our line of sight. After about eight and a half years, this forms a ring six light years in diameter, and some of this light may be scattered toward Earth to be seen. But this ring is also six light years closer to us than the star itself. The travel time for this light is therefore six years shorter, and so it arrives only two and a half years after the light from the initial burst (the eight and a half years between the two events, less the six years travel time difference for the light). This sort of phenomenon has also been responsible for jets from quasars appearing to travel at superluminal speeds.

Kullat Nunu
2005-Feb-03, 08:26 PM
That's the right answer. :)

Kullat Nunu
2005-Feb-03, 08:35 PM
A recent paper (http://arxiv.org/abs/astro-ph/0501604) in arXiv.org offers one solution to the enigma of V838 Monocerotis:


...Comparison with theoretical isochrones suggests an age of 4 million year for the system and a mass around 65 M(sun) for the progenitor of the outbursting component, which at the time of the outburst was approaching the Carbon ignition stage in its core. The 2002 event is probably just a shell thermonuclear event in the outer envelope of the star.